requested_toppings = ['mushrooms', 'green peppers', 'extra cheese']

for requested_topping in requested_toppings:
    if requested_topping == 'green peppers':
        print('Sorry, we are out of green peppers now.')
    else:
        print(f'Adding {requested_topping}.')

requested_toppings = []
if requested_toppings:
    for requested_topping in requested_toppings:
        if requested_topping == 'green peppers':
            print('Sorry, we are out of green peppers now.')
        else:
            print(f'Adding {requested_topping}.')
else:
    print("Are you sure you want a plain pizza?")

available_toppings = ['mushrooms', 'green peppers', 'extra cheese']
requested_toppings = ['mushrooms', 'french fries', 'green peppers']
if requested_toppings:
    for requested_topping in requested_toppings:
        if requested_topping == 'green peppers':
            print('Sorry, we are out of green peppers now.')
        elif requested_topping not in available_toppings:
            print(f"Sorry, we don't have {requested_topping}.")
        else:
            print(f'Adding {requested_topping}.')
else:
    print("Are you sure you want a plain pizza?")